Electrical device



Feb. 16, 1937. J. A. BECKER ELECTRICAL DEVICE Filed July 2, 1935 FIG.

L/UNTREATED PLATE Pun-E WITH VSINGLE LAYER FILM FILM AIR INSULATING FILM OFAN OIL OR A FATTY ACID INVE/V J. A.

70/? BECKER A T TOR/V5 V Patented Feb. 16, 1937 UNITED STATES PATENT OFFICE ELECTRICAL DEVICE Joseph A. Becker, Mountain Lakes, N. J assignmto Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation of New York Application July 2, 1935, Serial No. 29,441

11 Claims. (Cl. 175-366) This invention relates to electrical devices, and Such a device would be a condenser. A thin film, more particularly to a rectifier, condenser, or for example, of a single or a few mono-molecular the like and the method of making the same. layers thickness, of an insulating material on a An object of the invention is to produce an immetal member permits the passage of current proved electrical device of the aforementioned therethrough, the voltage-current characteristic types. being non-linear. If the film is between a pair A feature of this invention comprises an elecof similar metal plates, current will fiow in each trical device including an insulating film of one direction. The capacity of this arrangement, or more molecular layers thickness on a conhowever, is high and it is properly termed and is w ductive or semi-conductive member or layer. .usable as a condenser, although having a leaking Another feature resides in the method of makcharacteristic. The current passed may be deing such a device which comprises developing, creased by increasing the thickness of the film, producing or forming a film of the insulating mathe latter being strictly an insulator only when terial on a liquid and transferring the film to thick. When a semi-conductor is inserted bethe conductive or semi-conductive member or tween the thin film and one of the plates, agreater 5 layer. current flows in one direction through the unit Still other and further features will beapparent than in the reverse direction, and a rectifier is from the description which follows hereinafter. thus obtained. The insulating film is of an oil In accordance with this invention, a monoor a fatty acid that has been transferred to the molecular film or layer of an insulating material, member III by any suitable method. A preferred 20 for instance, an oil or a fatty acid, is formed on method will now be described with reference to a liquid, for instance, water, and transferred to Figs. 2 and 3. the surface of a conductive member, for instance, The receptacle or bath l5 contains a liquid IS, a metal plate, by dipping the member in the for example, water, upon whose surface afilm ll liquid and removing it. Additional layers of the of the insulating material, for instance, an odor 25 insulating material may be formed on the mema fatty acid, such as stearic acid, may be initially her by successive dippings. Subsequently, a layer developed as is already known by adding the inof a conductive or a semi-conductive material is sulating material to the liquid at the left of the placed in intimate contact with the insulating barrier, slide or partition l8, and adjusting the layer. position of the barrier until the layer is of a A more complete understanding of the invensingle molecular thickness. The portions IQ of tion will be obtained from the detailed descripthe partition are out of contact with the sides tion which follows hereinafter, read with referof the bath, the insulating film being prevented ence'to the appended drawing, wherein: from seeping through to the surface of the liquid Fig. 1 is a cross-section of an electrical device to the right of the partition by the air streams 35 embodying the invention: provided through the tubes 20.

Fig. 2 shows a plan view of a bath in which the I The plate ill at the left in Fig. 3 is shown just insulating film may be formed on a metal plate; before it is immersed in the liquid. If it is and desired merely to have a single layer of the in- 40 Fig. 3 shows a sectional elevational view of the sulating material on the plate, the latter will be 40 bath of Fig. 2 and a metal plate in various stages passed into the bath along the line A and reof treatment. moved from the liquid through the non-filmed The electrical device of Fig. 1 is an electric surface of the bath. If it is desired to have two current rectifier and comprises a disc, plate or layers on the plate, the latter is withdrawn from member In of a conducting material, for instance, the bath through the insulating film as indicated 45 a metal, having an insulating film ll of one or by the line B. Of course, when the plate is more molecular layers thickness on one surface. passed through the insulating layer, the filmv A layer l2 of a semi-conductor makes intimate adsorbed on the plate reduces the quantity of contact with the insulating film and is engaged the insulating material and the barrier is moved on its upper or outer surface by a second disc, to the left an amount sufficient to compensate 50 plate or member l3 of a conducting material, for the area of film removed, otherwise the monosuch as a metal. It will be understood, of course, molecular layer will be destroyed. If additional that the semi-conducting layer may be omitted layers are desired, the immersion and. removal and a device comprising the insulatingfilm ll procedure is continued the necessary number between the metal plates l0, I3 be obtained. of times. Subsequently, the film is removed from 55 l0, a film that covers the plate surface uniformly is obtained, the molecules in the film are oriented, and the number of mono-molecular layers can be accurately controlled. A test for orientation in some cases, is the action of water on the film after the plate has been removed from the bath. If the molecules are lined up on the'plate with one end of the molecule in contact with the plate, water'will stick to the film, while if they are lined up on the plate with the other end of each molecule in contact with the plate, water will roll off the film.

After the insulating film has been formed on the plate, a-layer of semi-conducting material, such as selenium, may be vaporized thereon, and another metal placed in contact with the selenium layer or vaporized thereon. When cuprous oxide is used as the semi-conductor, it is preferable to form the insulating film on it, in the manner outlined hereinabove, and thereafter to vaporize the metal layer In of Fig. 1 upon the insulating film.

While this invention has been disclosed with reference to a specific device and method of manufacture thereof, it is to be understood, of course, that the scope of the invention is to be considered as limited by the appended claims, only.

What is claimed is:

1. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of the insulating material on a liquid and transferring said film to said member.

2. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of the insulating material on water and transferring said film to said member.

3. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of oil on a liquid and transferring said film to said member.

5. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of a fatty acid on a liquid and transferring said film to said member.

6. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of stearic acid on a liquid and transferring said film to said member.

'7. The method of forming an insulating film on a conducting member of a rectifier, condenser or the like, which comprises developing a film of the insulating material on a liquid and transferring said film to said member by dipping said member in said liquid.

8. An electrical device comprising a conductive member, a mono-molecular film of an insulating material formed on said member, and conductive means in intimate contact with said film.

- 9. An electrical device comprising a conductive metallic member, a mono-molecular film of an oil on said member, a. layer of a semiconductive material in intimate engagement with said oil layer, and a conductive member engaging with said semi-conductive layer.

10. An electrical device comprising a conductive member, a mono-molecular, oriented film of an insulating material on said member, and conductive means in intimate contact with said film.

11. The method of forming an insulating film on a member of a rectifier, condenser or the like that comprises developing a layer of the insulating material on a portion of the surface of a. liquid, passing the conducting member through the layer and into the liquid, a film being thereby transferred to the conducting member. and withdrawing the member from the liquid through the portion of the surface having no insulating layer thereon.

JOSEPH A. BECKER. 

